depends on the person. however, don't fret. many colleges will consider your first semester freshman year grades (if they even give a stuff about them really) not as essential, as it's considered a "transition period" for freshman during that time due to the middle/high school changes.
but get your grades up.
Oh god, when people say they only have bad grades because they're too smart are full of stuff. Having that attitude in the real world isn't gonna do anything good for you ever.
no, they're just dumb and trying to pass it off as "too smart" when really they're just lazy as stuff and inattentive.